To the forum:

The problem I have does not involve a PIC; however, there appears to be
an abundance of knowledge in this forum regarding electronics based on
some of the messages I've read so far.

Is there anyone out there in the forum that has experience with Design of
Experiments (Taguchi-type) in addition to their electronics
troubleshooting skills.  I have been seeing repetitive problems with a
MM54C14J Hex Inverter (an old ceramic-style part) where the Vcc is
getting creamed.

Because the explanation of the failure will be a bit too long to
adequately put into a message, the best place to get further details of
the failure type is to go to
http://web.gmtcom.com/~k3jsch/sixsigma/access.htm

The problem occurs regardless of the following:

1) Whether it has been in service for only a few hours or at least 8000
hours.
2) Whether it is operating at a temperature of 55 degrees C or slightly
past 100 degrees C

3) Whether it is operating in a 60Hz domestic unit or a 50Hz overseas unit.

4) date code of IC

Any suggestions, etc., are welcome.  What I am trying to do is set up an
experiment at our production facility to inject noise, etc. into the
design as it is running.  Factors I am looking at are :

1) Levels of noise voltage to inject into the cable between the
microprocessor unit that this IC resides on and the gate firing board of
the SCR bridge that is directly mounted over the 3-phase, 6SCR bridge
that ultimately runs either the left track or right track motor.

2) Brand name of chip.

3) Whether or not modification to the shielded cable and/or its placement
in the circuit would make a difference.


Regards,

Kelly Schauf
k3jsch@mail.gmtcom.com